14 Moments That Defined Twitter

Over the past seven years, Twitter has evolved into a medium where anyone with an Internet connection can tune in to see celebrities spar, tragedies unfold, and news break—on both a local and global scale. On the eve of the company's initial public offering on the New York Stock Exchange, which is poised to surpass Google's as the second-largest Internet IPO in history, we took a look at 12 moments that shaped Twitter history.

1. Hello, world
Cofounder Jack Dorsey sends his first-ever tweet to the world in 2006:An early Twitter blueprint written by cofounder Jack Dorsey.

3. Miracle On The HudsonCaptain Chelsea "Sully" Sullenberger wasn't the only person who made headlines when he successfully landed a plane full of passengers on the Hudson River after a double-bird strike. Twitter user Janis Krums snapped a photo of the plane moments after landing that was shared and used by media organizations all over the world, sealing Twitter's reputation as a breaking news source. Twitter would go on to become an instrumental platform for citizen and professional journalists alike during major events like the Arab Spring and the London riots.

4. "RT If You Like Twitter"
"Retweet is a button that makes forwarding a particularly interesting tweet to all your followers very easy," Stone wrote in a 2009 blog post. "In turn, we hope interesting, newsworthy, or even just plain funny information will spread quickly through the network making its way efficiently to the people who want or need to know." What started as a small release eventually became one of the most important, defining features of the current version of Twitter.

5. FEELING REALLY 21st CENTURY
In a testament to Oprah Winfrey's influencing power, an on-air interview between Winfrey and then-Twitter CEO Evan ("Ev") Williams helped Twitter's traffic jump 43% week-over-week in November 2009. It also gave us one of the most memorable Twitter exchanges of all-time:

6. The beginnings of a business model
In the early years of Twitter, cofounder Biz Stone sat for an interview with Stephen Colbert, who inquired, "So, I assume that ‘Biz’ in ‘Biz Stone’ does not stand for ‘Business Model’." But in April 2010, Stone wrote a blog post introducing Promoted Tweets, a paid service for advertising partners who wanted their tweets to reach large swaths of users. Best Buy, Bravo, Red Bull, and Starbucks were among the first launch partners.

7. The Library of Congress to archive every single tweet ever
In 2010, the Library of Congress signed an agreement with Twitter to take on the Herculean task of archiving what amounted to 170 billion tweets as of this January, when deputy librarian Robert Dizard told Fast Company: "I look at Twitter as a start of what the Library will be doing in the medium and long-term, not a test of whether we’ll collect social media at all."

8. All eyes on Hollywood
Even as they were flanked by celebrities, Twitter's media execs only had eyes for their screens at the MTV Video Music Awards in September 2010, the scene of an aggressive push to integrate Twitter with a live television event, the largest integrated-TV initiative the company had taken to date. Live events, and television in general, would eventually become of great interest to Twitter execs looking to court both celebrities and their entertainment-hungry fans.

9. An $8 billion valuation
In July 2011, Twitter raised a massive, record-breaking $800 million round of venture capital funding. Half that money went toward paying out early employees and investors looking to cash in their privately held common stock.

11. Twitter suspends a journalist for criticizing its Olympics coverage partner, NBC
During the London Olympic Games in the summer of 2012, Twitter suspended journalist Guy Adams, allegedly for posting the NBC Olympics president Gary Zenkel’s work email address, although Adams had been tweeting a string of criticisms of NBC's coverage. (Twitter later reinstated Adams' account.)

12. An entrepreneur frustrated with Twitter and Facebook creates App.net, an ad-free, paid social network
In August 2012, entrepreneur Dalton Caldwell launched App.net, a paid, ad-free, alternative social network, after expressing his frustrations with both Facebook and Twitter's for "screw with users and third-party developer ecosystems, all in the name of ad-revenue." App.net would go on to amass more than 30,000 users in its first six months.

13. Twitter acquires Vine
Although Twitter had made a number of small acquisitions by the time it picked up a small video startup called Vine last October, it had never ventured into video content. A year later, Airbnb has used Vine to make a short film; Internet guru Gary Vaynerchuk has his own Vine talent agency, and Facebook has launched its own competitor with Instagram video.

14. On the road to IPO
After years of speculation, Twitter finally filed for an IPO on September 12, 2013. A few weeks later, as TWTR gears up for its NYSE debut, Twitter sets its final stock price at $26 a share, up from a previous low of $17.